1. Field of Invention
This invention relates to electrical connectors known as a smart card readers, into which smart cards are inserted to a reading position where contact elements provided in the smart card reader engage contact pads on the smart card to provide temporary electrical connection to allow for both reading and writing data to and from the smart card.
2. Discussion of Prior Art
This invention relates generally to the field of electronic cards more commonly known as Integrated Circuit Cards (ICC), smart cards, or chip cards, and to the apparatus known as a smart card reader which provides temporary electrical connection with the smart card's microprocessor/memory contacts (pads) on the surface of the card. More specifically, this invention relates to a compact (small) smart card reader into which smart cards are repeatedly inserted, temporarily engaging the card's contact pads with contacts in the smart card reader when the card is fully inserted to a card-reading position as indicated by a switch.
Smart cards, or chip cards are the same size as credit cards (ref: ISO7816 & ISO7810 standards), and used for applications requiring data transfer in either secure or non-secure environments. They are most commonly used for credit/debit transactions in the retail industry, but additional applications for smart cards are gaining in popularity these include: personal identification, computer system access control, so called ‘closed systems’ for payments/identification, medical records storage cards, etc. All smart cards contain a set of gold-plated metallic contact pads located on the surface of the card (according to ISO7816 standards), which are internally connected to either a microprocessor, or memory chip. The smart cards are inserted into smart card readers which make electrical connection to the pads on the smart card through contacts mounted within the smart card reader. After electrical contact is made, communication with the card can be established so that data can be bi-directionally transferred between the card and a host processor using the smart card reader as an electrical conduit.
As smart cards become more prevalent, new applications are becoming popular, such as small countertop point-of-sale (POS) terminals, handheld POS terminals, portable data acceptors (PDAs), personal identification number (PIN) verification terminals, etc. These devices require a smart card reader which is compact, robust, (i.e. designed for over a million card cycles), and can be easily mounted into a housing without requiring a host printed circuit board for support. In all point-of-sale applications, banking associations Visa and Mastercard now require that all smart card readers be tested by accredited laboratories to ensure they are in compliance with Europay/MasterCard/Visa (EMV) standards. Smart card readers that are proved to be in compliance are granted EMV certification. Because of that requirement, the terminal industry needs a compact smart card reader that is EMV certified, which additionally allows them the flexibility of designing their terminal without requiring them to get the smart card reader certified. Compact smart card readers currently on the market must be mounted on an external printed circuit assembly (PCA). In addition the PCA is necessary to provide electrical connection to their contacts. That means the terminal manufacturer must design a PCA that mechanically supports the compact smart card reader, provides electrical connections from the reader, routes signals to its host processor, and then submit that PCA/Reader for certification. A compact reader that has an integral PCA would eliminate this requirement for certifying the reader every time the PCA design is changed for a new terminal application
There are currently two types of smart card reader connectors: a “sliding” type, and a “landing” type. One example of a compact sliding-type reader is disclosed in U.S. Pat. No. 6,655,590 Dec. 2, 2003 by McFeely, et al, which discloses a reader where a smart card is inserted into the reader, and consequently slides over the connector contacts until it is fully inserted. The smart card reader's contacts are spring-loaded, exerting a normal force onto the smart card's surface, starting at the front edge of the card until the fully-inserted position, on both insertion and withdrawal of the card. Upon full insertion, the smart card reader's contacts align with the smart card's contact pads.
This type of contact presents a problem in that the reader's contacts sustain continuous wear from riding on the surface of the card throughout the insertion and withdrawal process. That action generates debris, which is picked up by the reader's contacts, and may contain material that serves as a dielectric, making it more difficult to obtain a reliable electrical connection. Another problem is created in that the wiping action of the contacts will mar any graphics within their path on the card, and will cause wear of the reader's contacts, severely limiting their operating life. This type of contact is typically used in applications that require only a limited number of card insertions/withdrawals and are not subject to abuse or debris, such as a home PC access reader or television set top box smart card reader. This reader is installed by soldering its smart card contact legs to an external printed circuit board that is part the host terminal.
An example of the landing type of smart card reader is disclosed in U.S. Pat. No. 5,936,222 Aug. 10, 1999 by Korsunsky, et al, where the contacts are designed with each having a leg passing through a base (reader frame) for electrical connection with a printed circuit assembly. An arm extending from the leg is substantially perpendicular to the leg, and pivotal in relation thereto. A contact point is disposed on the arm at a first end towards the mating surface and an actuating section is disposed on the second end opposite the mating face. Upon insertion of a card into the smart card reader, the contact point will not engage the major surface of the card until the card engages the actuating section, causing the arm to pivot about the leg to exert a normal force on the contact points of the card sufficient to establish electrical connection. This type of contact presents a problem in that the actuating portion of each contact must exert a normal force to the card's surface until the card is fully seated. That force is concentrated in a small surface area which creates considerable wear and debris which will substantially reduce the active life of a card, since the actuating portion of the card will wear from repeated insertions. Moreover, the reader does not have any openings for the debris to exit the reader. That debris can therefore be picked up by the contacts, which can result in an unreliable electrical connection between the card's pad and the smart card reader's contacts. Another limitation of this ‘pivot’ design is the limited pivot action provided by the relatively short lever arm on the contact, restricting the contact area of the pivot from maintaining a consistent force on bowed, or worn smart cards. This design requires an external printed circuit board to obtain electrical connection to the contacts, and physically mount the smart card reader
One common condition for prior-technology compact smart card readers, is that their design required that they be secured (soldered) to a printed circuit board to provide both mechanical support for the smart card reader's chassis, and electrical connection with the reader's contacts. The end user was therefore required to design a printed circuit board that mated with the compact smart card reader, and also positioned the reader appropriately in the enclosure.
Another example of a prior technology compact smart card reader is disclosed in U.S. Pat. No. 5,252,815 Oct. 12, 1993 by Pernet, which shows a smart card reader with sliding type contacts, soldered to a PCA which in turn is soldered/riveted to a case (housing). The invention's stated objective is to create a smart card reader “ . . . of reduced overall dimensions and cost . . . ”. The invention described in said patent results in a reader that is not very compact, or robust which has sliding contacts, and has a chassis that cannot be easily integrated (mounted) inside a terminal housing. This prior technology for a compact smart card reader does not provide for applications that require over one million cycles due to the sliding type of contact design which creates substantial contact wear. Prior technology for compact smart card readers does not provide for an internal printed circuit board, which requires the end user to design a printed circuit board for providing electrical connection with the reader's contacts, and card seated switch.
The one consistent feature that existing compact smart card readers have is that they cannot be secured to a housing without additional mounting brackets and/or printed circuit boards. That ability is only available in substantially larger, and mechanically more complex, smart card reader designs such as the one disclosed in U.S. Pat. No. 5,554,840 Sep. 10, 1996 by Saroya. That reader provides a landing contact and integral printed circuit board, but is substantially more complex, expensive, larger, and is not suitable for mounting in a handheld, or small countertop terminal.
Among the design problems facing handheld product manufacturers is the limited depth of the handheld terminal. That lack of depth, results in most handheld readers being designed with the smart card insertion slot located on the front or back surfaces of the terminal, rather then the top surface where it is easily seen and more accessible to the user. The main reason for that, is that the design of prior-technology smart card reader contacts does not allow for a smart card to be inserted to a minimum depth. Therefore, those readers require a deeper (longer) reader housing which cannot be postitioned on the top surface of most handheld terminals.